stevie
Junior Member
Joined: November 2020
Posts: 55
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Post by stevie on Mar 5, 2021 17:19:50 GMT -5
No, thanks to you. I'm finally going to have a try at it today and see what happens. My pal is a real pro so he should be able to take over if I have trouble.
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stevie
Junior Member
Joined: November 2020
Posts: 55
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Post by stevie on Mar 6, 2021 21:31:35 GMT -5
Struggle on the TIG the spot welder on the other hand... just for fun.
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Post by racket on Mar 6, 2021 21:38:19 GMT -5
LOL....Bit like my efforts :-(
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stevie
Junior Member
Joined: November 2020
Posts: 55
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Post by stevie on Mar 6, 2021 21:52:14 GMT -5
Yeah then my shopmate came over and grabbed the TIG I have been blasting through the practice stuff all day only burning stuff up. Back to practice.
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stevie
Junior Member
Joined: November 2020
Posts: 55
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Post by stevie on Mar 18, 2021 22:39:46 GMT -5
After burning through all kinds of scrap and hours of time I have made tig welds today in this .024 material. Sounds boring for those of you with experience but it is a high water mark here.
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ausjet
Veteran Member
Joined: May 2013
Posts: 133
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Post by ausjet on Mar 19, 2021 5:12:53 GMT -5
Hi Stevie, here is a bit of a cheat sheet I’ve made from what I’ve discovered over the years, always adding to it as I learn more 😂 might help you out.
TIG WELDING STAINLESS
-Prep is key, wire brush, deburr edges, clean with acetone/isopropyl alcohol. -Ensure fit up is as tight as possible. -Use a gas lense -The bigger the cup the more cfh gas flow you need. Start at 20cfh for a size 12 for example..the big furic fupa ones need like 30-40cfh (14-18lpm) -The smaller cup size you go, the less trailing gas coverage you get- one of the reasons you generally use bigger cups for stainless. -The bigger the cup the more stick out you can have. But try keep it at the minimum end of the scale unless a long stick out is required in a tight spot for example. -6 seconds post flow. Once you finish the bead, hold the torch there and let the post flow continue shielding the weld. -Have torch angle just off vertical on a push angle. (Too steep of a push angle reduces gas coverage on the weld behind) -Keep filler wire inside the gas coverage between dabs (otherwise filler wire oxidises and contaminates weld puddle). -1amp per thou of stainless thickness subtract 10% -(40amps per mm) 47amps for 1.2mm -10%= 42amps -42a for 1.2mm stainless -55a for 1.6mm stainless -keep a super tight arc to keep the heat down -3/32 tungsten 2% lanthanated is a good all round tungsten for stainless and Ali. 1/16 is good for thin stuff..2mm and less -Try pulse settings if struggling to keep the heat down on thin stuff..1.4ppm 10-15% background current. -7 to 10cfh back purge (3-5lmin) back purge not only prevents sugaring of the backside weld but also prevents a concave weld puddle(weld puddle sinking) -sharply ground tungsten eg 20degree produces a larger arc cone and less penetration than say a 45degree grind which is ideal for me- produces a nice pinpoint arc. -keep your tungsten clean. If you dip it, stop and regrind. A contaminated tungsten makes for a very unstable arc
ALUMINIUM
-As with stainless, prep is key, wire brush, deburr edges, clean with acetone/isopropyl alcohol. Ensure fit up is tight -Gas lense not needed -Generally with non reactive metals you want smaller cup sizes and lower flow gas. -Big cup sizes make the arc want to follow the gas as it spreads making it wander. This leads to an inconsistent cleaning action affected zone. -The higher the frequency the more tight the arc becomes. -Thin aluminium(3mm and less)- 100-120hz+ and a tad more cleaning action (less heat into part) -Thick aluminium- 80hz.. or even lower -For contaminated material eg a cast engine oil sump, hover the torch around the area and let the cleaning action bake off contaminates before initiating the puddle.
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stevie
Junior Member
Joined: November 2020
Posts: 55
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Post by stevie on Mar 19, 2021 16:31:57 GMT -5
Thank you so much. A kit with the cups and lens arrived today so I will have at it again. I am very happy there was so much scrap.
Edit- Ok this gas lens set really made a difference I believe I am ready to weld all this material. Thank you everyone for the tips!
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stevie
Junior Member
Joined: November 2020
Posts: 55
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Post by stevie on Apr 3, 2021 22:15:34 GMT -5
The 18ga material would have been a better choice. Accomplishing (ish) welding this .024 material however has been an endeavor. Just an engineering note for those that follow. Rolling 18ga material may be an easier path. That being said these pro welders have come here and they can not believe I am doing this with .024 as I am learning.
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stevie
Junior Member
Joined: November 2020
Posts: 55
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Post by stevie on Jun 29, 2021 22:14:32 GMT -5
Although I can at times get this 24ga material to work, it is really rather difficult for the welds that are free in the air without a backing plate of bronze or aluminum. 18ga should give me a better shot at it. No problem cutting it again on the waterjet. Before I do this though, any changes to the geometry on this thing? Lemme upload a file or 2. I think I have calculated the combustor correctly, I wonder about the AB injector as well as the taper of the AB. Once this is together it will be hard to get to the AB injector. I looked at it as a smoke machine, lots of small holes dump as much as you can in there.
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stevie
Junior Member
Joined: November 2020
Posts: 55
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Post by stevie on Jun 29, 2021 22:37:51 GMT -5
The AB is Andy Morris, great job. Flame tube is the calculator. AB injector is 2.5 dia, 1.25 in the center and .1 holes. And as always, thank you. Steve
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slittlewing
Senior Member
Joined: November 2017
Posts: 458
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Post by slittlewing on Jul 5, 2021 7:20:57 GMT -5
Hi Stevie,
I would suggest you have way too many fuel holes in your injector ring and they are too large diameter. I think your turbo is ~74mm Inducer? My 69mm Inducer Turbo feeding an AB Fuel Ring with 8x 1.0mm Holes which has been well proven by others in the past. At full tilt, I am using only 50% PWM on my 044 Pump to feed the AB, so there should be plenty of headroom for your extra 15% airflow with this hole setup.
Cheers Scott
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stevie
Junior Member
Joined: November 2020
Posts: 55
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Post by stevie on Jul 6, 2021 18:37:56 GMT -5
Thanks!!! Steve
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stevie
Junior Member
Joined: November 2020
Posts: 55
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Post by stevie on Jul 21, 2021 20:54:02 GMT -5
Lol. I can just MIG this 18ga material. I'll try the TIG on it to see but what a difference.
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stevie
Junior Member
Joined: November 2020
Posts: 55
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Post by stevie on Dec 9, 2021 8:00:14 GMT -5
Ok finally moving along, kart is a roller with brake. It took a while as it was given to me as a pile of mismatched parts. Tons to do but fun. Steve
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stevie
Junior Member
Joined: November 2020
Posts: 55
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Post by stevie on Dec 9, 2021 21:41:39 GMT -5
Ok, with all the CNC and welding and chilling and lifting and positioning and testing equipment we have here sheet metal is a dead zone. Its hilarious. Standing by millions of dollars of precision stuff I have to make this janky sheet metal bending rig. Surprise! it works a hell of a lot better than I expected. And it feels good to have hands on it. Steve
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